Wow! that's rough

[aoriii]

My '85 has a HORRIBLY rough ride. I know these cars are low and are supposed to have a 'feel' of the road, but the shake is absolutely bone-jarring :ugh !! I'm trying to get an idea of where I can start to make this a more pleasant car to drive. I've replaced the shocks all-around, and that helped a little (admittedly I didn't go with Billstein's, but at the time I had to hold to certain financial constraints).

Where is the best place to start trying to smooth out the ride. I've noticed there are no springs on the front of the car, and that seems very odd. But there doesn't appear to be any attatchment points either. Is there an aftermarket coil-over spring shock that could help?

thanks

 

[jiangtao]

You probably have a Z51. Look in the storage compartment behind the driver's seat for the RPO codes. If it's a Z51 then you will see the code for it in there.

 

[JonM]

Make sure your tires are balanced...and the spring is the large fiberglass arch looking (transverse) thing running from one side to the other.

 

[Lar99]

Tire Pressure

I've noticed tire pressure can really effect the ride. Set tires at the stated pressure on the drivers door for the best ride.

 

[tigmaned]

i am wondering what kind of car your comparing the ride to??? its not a caddy your driving. C4 vettes have transverse compsite leaf springs in front and in back. some say the camber brace from R-D racing will help too.

 

[jester]

How old are your times?

I noticed a big difference when I replaced my 13 year old original equipment tires. They were getting pretty hard.

 

[JRMaroon]

I noticed a big difference when I replaced my 13 year old original equipment tires. They were getting pretty hard.

I agree. When I replaced the original GSC's with Goodyear Eagle F1-GS D3's my ride and handling improved.

Jeff

 

[aoriii]

Yes, it is a Z51 handling package.

Comparison- I'm comparing the ride to everything that I sit in, from pickup trucks to a dodge neon, to a friends 01 Trans Am. I realize that corvettes ride tight and hard, but this seriously uncomfortable.

Tires - Tires are new - less than 1000 miles on them, just balanced Faulken's


JonM - I've noted the transverse spring in the rear, but don't see any sort of spring or support in the front, besides the control arms. The car has about 70K miles on it, should the rear transverse spring be worn out at that age??


Thanks for all the feedback. I'm sure all the people around here know questions to ask that I've not even thought of.

 

[tnovot]

My '85 has a HORRIBLY rough ride. I know these cars are low and are supposed to have a 'feel' of the road, but the shake is absolutely bone-jarring

Not sure what exactly you mean by shake. Are you talking simply about a harsh ride or do you actually feel vibration and shimmy through the steering wheel? Do your legs and upper body shake and vibrate when going down the road? If so, you could have a tire out of balance, bent wheel, or an alignment problem.
If you are talking about feeling all the little cracks and bumps in the road, I totally agree with previous comments about old tires with hardened rubber giving a harsh ride.
And yes, as previously stated, you are not driving a Caddy. Maybe you should try to find one or two other Corvettes from the mid 80's to drive as a reference for comparison
Terry

 

[Tuna]

The early C4s with Z51 have a reputation for being a real teeth jarring ride. They also cornered at 1.00g. Not intended as a daily driver if you ask me.

They came with higher spring rates, bigger roll bars and stiffer shocks. Don't even think about driving it without the roof installed.

The front spring is the big black plastic thing inside the lower control arm and it extends through the front cross frame to the opposite lower control arm. At 70K, they should not be worn out. There are things that can cause the springs to delaminate and crack however. So, you might want to check them closely.

I can't think of any car or truck that rides as harsh as an early C4 with Z51 option except maybe a 1944 Army Jeep!

Doug Rippie Motorsports (?) makes a coil over conversion kit for the C4 if you really want to change the ride and spend some money.

 

[Hot Rod Roy]

Your '85 with Z51 suspension isn't built to ride smooth, it's built to handle! It's a race car for the highway! If you want it to ride better, you'll have to change the springs. The rear spring from an '86 or later with the FE1 suspension is less than half the stiffness of your rear spring, so that will make a big difference (88 N/mm vs. 40 N/mm). Changing the rear spring is the first thing you should do to improve the ride of your '85. You don't need coil-overs, you only need later model springs.

 

[Edmond]

What kind of shocks did you go with? Personally, I like the stiff rides but then again, I have a Z52 so that's not as stiff as the Z51.

 

[aboatguy]

Part of the C4 evolution was improving the ride quality. Notice I said ride quality and not handling. As previously posted the first C4s were excellent handling cars. However, the average corvette owner did not like the harsh ride so GM expiremented with softer springs, different shocks, sway bars etc in an effort to soften the ride and keep suitable handling. You can improve your ride with softer springs from one of the later C4s.

 

[RV Guy]

I agree. When I replaced the original GSC's with Goodyear Eagle F1-GS D3's my ride and handling improved.

Jeff

How is the road noise with these tires?

Thanks

 

[RV Guy]

They came with higher spring rates, bigger roll bars and stiffer shocks. Don't even think about driving it without the roof installed.

Just curious, what difference does the roof installed or not make?

Thanks

 

[aboatguy]

Just curious, what difference does the roof installed or not make?

Thanks

SHIMMY SHIMMY SHAKE! :L

Some off the Z51s will shake you to death with the top off.

Mike

 

[RV Guy]

SHIMMY SHIMMY SHAKE! :L

Some off the Z51s will shake you to death with the top off.

Mike

Interesting, I have the Z51 option on my '86 and I have only run it a couple of times with the top off. I hadn't noticed any difference.

 

[speedmaster4]

mine is z-51. NOT comfy for normal road use. bought a standard rear spring for $50 @ j-y supply and use it most of the time. takes about 30 min to change back to z for autocross, real ez after first time. actually went back and got the stand front, but tried auto-x with z-front and stand-rear just for giggles and noted increased push but def not uncontrollable.

 

[1986coupe]

Has the car been lowered? If so then you will get a terribly rough ride. When you look at the front spring you should see a rubber piece on the end of it. It can be viewed by simply looking down at the spring and the end will get bigger because of the rubber on the end. If you don't see that then it can explain some of the problem.
Does the car bottom out?

 

[aboatguy]

Has the car been lowered? If so then you will get a terribly rough ride. When you look at the front spring you should see a rubber piece on the end of it. It can be viewed by simply looking down at the spring and the end will get bigger because of the rubber on the end. If you don't see that then it can explain some of the problem.
Does the car bottom out?

Unlike conventional suspensions you can lower a C4 without affecting ride quality due to the leaf spring. Instead you installing shorter coil springs(stiffer) you raise the transverse leaf in its mounting point so the car drops and you did not affect the spring rate at all.

I have lowered my car, my ride quality did not change, and my car has not bottomed out the suspension.
Have you lowered your car? How can you see the rubber on the end since the piece that is trimmed is between the spring and the lower a-arm?

Part of the C4 evolution was improving the ride quality without compromising the handling (too much)
My car rides pretty darn good however, if you look at the pictures I installed polybushings which will provide a little harsher ride than the rubber bushings. Spring rates will change the ride quality dramatically. So his easiest fix is to go with softer springs.

JMO
Mike